/Engine/Plugins/Experimental/Mutable/Source/CustomizableObject/Classes/MuCO/CustomizableObjectInstance.h
Increases the range of values of the integer with ParamName, returns the index of the new integer value, -1 otherwise. The added value is initialized with the first integer option and is the last one of the range.
[UFUNCTION](Programming/UnrealArchitecture/Reference/Functions)(BlueprintCallable, Category=CustomizableObjectInstance) int32 AddValueToIntRange ( const [FString](API\Runtime\Core\Containers\FString) & ParamName )